Keyboards of various kinds have been utilized for many years to permit the manual encoding of information. A well known example of an early keyboard is the manual typewriter wherein each key button may be depressed to mechanically imprint the alphanumeric character desired upon a piece of paper. Mechanical linkages between the key button and the mechanical arm bearing the desired character were later replaced with an electrical switch which energizes a motor driven arm. With the increasing capability of electronics and the development of computers, a typical typewriter keyboard may be utilized in an ever increasing number of devices for encoding information including cash registers, calculators and word processors.
The flexibility of electronics often enabled the same keyboard to be utilized in the different devices mentioned. Often, the same device with the same keyboard may be sold into different countries, with different alphanumeric characters upon the various keys.
Thus, depending on the function of the keyboard desired, different keys or push buttons can be labeled with varying alphanumeric characters. Some of these keys or push buttons can be placed upon the keyboard and then inhibited from operation depending upon the equipment in which the keyboard is to be installed, the desired function of that equipment, and the country into which the equipment is to be sold. Once the equipment is in field operation, it may be desired to modify the equipment to change the alphanumeric character upon the keyboard, to enable one of the disabled keys or to disable another.
The prior art addresses, the problem of modifying the functions of operating keys upon a keyboard in U.S. Pat. No. 4,119,839 by U. L. Beckmann, et al. It is also known to inhibit the manual depression of one key when an adjacent key has been depressed or to retain one key in a depressed position until the depression of an adjacent key. See for example U.S. Pat. No. 3,412,221 by A. A. DiPilla which utilizes a clip to prevent the depression of one key when an adjacent key is depressed. See also U.S. Pat. No. 3,626,120 by D. H. Wright which retains one key in a depressed position until an adjacent key has been depressed.
None of these devices nor any device currently known teach the utilization of an economic keyboard spacer which may be easily installed or removed from beneath a key button to respectively inhibit or enable manual operation of the keyboard switch.